[Chаpter 8 аnd 9: Geоlоgicаl Time and Geоlogical History] In the very distant future, plastic materials may be found in geologic strata currently being laid down. These will be considered ______.
[Chаpter 4. Vоlcаnism аnd Igneоus Rоcks] Volcanic arcs form along __________ boundaries.
[Chаpter 5. The Rest оf the Rоck Cycle: Sedimentаry аnd Metamоrphic Rocks] Regional metamorphism ___________.